Patents by Inventor Rama Nand Singh
Rama Nand Singh has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20110173577Abstract: Techniques for improving circuit design and production are provided. In one aspect, a method for virtual fabrication of a process-sensitive circuit is provided. The method comprises the following steps. Based on a physical layout diagram of the circuit, a virtual representation of the fabricated circuit is obtained that accounts for one or more variations that can occur during a circuit production process. A quality-based metric is used to project a production yield for the virtual representation of the fabricated circuit. The physical layout diagram and/or the production process are modified. The obtaining, using and modifying steps are repeated until a desired projected production yield is attained.Type: ApplicationFiled: February 1, 2008Publication date: July 14, 2011Applicant: International Business Machines CorporationInventors: Ching-Te K. Chuang, Fook-Luen Heng, Rouwaida Kanj, Keunwoo Kim, Jin-Fuw Lee, Saibal Mukhopadhyay, Sani Richard Nassif, Rama Nand Singh
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Patent number: 7962865Abstract: A system and method of employing patterning process statistics to evaluate layouts for intersect area analysis includes applying Optical Proximity Correction (OPC) to the layout, simulating images formed by the mask and applying patterning process variation distributions to influence and determine corrective actions taken to improve and optimize the rules for compliance by the layout. The process variation distributions are mapped to an intersect area distribution by creating a histogram based upon a plurality of processes for an intersect area. The intersect area is analyzed using the histogram to provide ground rule waivers and optimization.Type: GrantFiled: July 17, 2008Date of Patent: June 14, 2011Assignee: International Business Machines CorporationInventors: Fook-Luen Heng, Mark Alan Lavin, Jin-Fuw Lee, Chieh-yu Lin, Jawahar Pundalik Nayak, Rama Nand Singh
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Publication number: 20090089726Abstract: A method for layout design includes steps or acts of: receiving a layout for design of an integrated circuit chip; designing mask shapes for the layout; transmitting the mask shapes to a litho simulator for generating wafer shapes; receiving the wafer shapes; calculating electrically equivalent gate lengths for the wafer shapes; analyzing the gate lengths to check for conformity against a threshold value, wherein the threshold value represents a desired value of electrically equivalent gate lengths; placing markers on the layout at those locations where the gate length violates the threshold value; and generating a histogram of gate lengths for comparing layouts for electrically equivalent gate lengths for layout quality.Type: ApplicationFiled: October 1, 2007Publication date: April 2, 2009Applicant: International Business Machines CorporationInventors: Fook-Luen Heng, Mark A. Lavin, Jin-Fuw Lee, Thomas Ludwig, Rama Nand Singh, Fanchieh Yee
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Publication number: 20080301624Abstract: A system and method of employing patterning process statistics to evaluate layouts for intersect area analysis includes applying Optical Proximity Correction (OPC) to the layout, simulating images formed by the mask and applying patterning process variation distributions to influence and determine corrective actions taken to improve and optimize the rules for compliance by the layout. The process variation distributions are mapped to an intersect area distribution by creating a histogram based upon a plurality of processes for an intersect area. The intersect area is analyzed using the histogram to provide ground rule waivers and optimization.Type: ApplicationFiled: July 17, 2008Publication date: December 4, 2008Inventors: Fook-Luen Heng, Mark Alan Lavin, Jin-Fuw Lee, Chieh-yu Lin, Jawahar Pundalik Nayak, Rama Nand Singh
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Patent number: 7448018Abstract: A system and method of employing patterning process statistics to evaluate layouts for intersect area analysis includes applying Optical Proximity Correction (OPC) to the layout, simulating images formed by the mask and applying patterning process variation distributions to influence and determine corrective actions taken to improve and optimize the rules for compliance by the layout. The process variation distributions are mapped to an intersect area distribution by creating a histogram based upon a plurality of processes for an intersect area. The intersect area is analyzed using the histogram to provide ground rule waivers and optimization.Type: GrantFiled: September 12, 2006Date of Patent: November 4, 2008Assignee: International Business Machines CorporationInventors: Fook-Luen Heng, Mark Alan Lavin, Jin-Fuw Lee, Chieh-yu Lin, Jawahar Pundalik Nayak, Rama Nand Singh
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Publication number: 20080066047Abstract: A system and method of employing patterning process statistics to evaluate layouts for intersect area analysis includes applying Optical Proximity Correction (OPC) to the layout, simulating images formed by the mask and applying patterning process variation distributions to influence and determine corrective actions taken to improve and optimize the rules for compliance by the layout. The process variation distributions are mapped to an intersect area distribution by creating a histogram based upon a plurality of processes for an intersect area. The intersect area is analyzed using the histogram to provide ground rule waivers and optimization.Type: ApplicationFiled: September 12, 2006Publication date: March 13, 2008Inventors: Fook-Luen Heng, Mark Alan Lavin, Jin-Fuw Lee, Chieh-yu Lin, Jawahar Pundalik Nayak, Rama Nand Singh
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Patent number: 7018746Abstract: A method of verifying the placement of sub-resolution assist features (SRAFs) in a photomask layout is described. SRAFs are added to the photomask layout to enhance the process window for semi-isolated and isolated features. Rules are provided to automatically place the SRAFs into the layout. When deficiencies are detected in the assist feature design or in the automated SRAF placement program, the placement of SRAFs requires verification. The method verifies the correct placement by defining a unique image property linked to the accurate placement of the assist features, and combines it with in-situ image simulation of the individual layout.Type: GrantFiled: April 15, 2003Date of Patent: March 28, 2006Assignee: International Business Machines CorporationInventors: Yuping Cui, Rama Nand Singh
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Patent number: 6985169Abstract: An image capture system for mobile communications systems includes an imaging device for capturing optical image data and a data transfer apparatus coupled to a communications device communications device for transferring the optical image data to the communications device for transmittal over a communications network.Type: GrantFiled: February 9, 1998Date of Patent: January 10, 2006Assignee: Lenovo (Singapore) Pte. Ltd.Inventors: Zhong John Deng, Sudhir Muniswamy Gowda, John P. Karidis, Dale Jonathan Pearson, Rama Nand Singh, Hon-Sum Philip Wong, Jungwook Yang
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Patent number: 6816225Abstract: A display device and method for fabricating a liquid crystal cell are disclosed. A liquid crystal cell includes a first substrate, and a second substrate attached to the first substrate. The first substrate has a same thickness as the second substrate. The first substrate is lapped at a first rate while concurrently lapping the second substrate at a second rate, which is different from the first rate. The first substrate and the second substrate are thinned to different thicknesses. The thinner of the first and second substrates is provided on a viewer side of a collimate and post diffuse type liquid crystal cell to reduce depixelization.Type: GrantFiled: June 26, 2001Date of Patent: November 9, 2004Assignee: International Business Machines CorporationInventors: Evan George Colgan, Fuad Elias Doany, Tomohito Jounai, Satoshi Maruyama, Hideo Ohkuma, Rama Nand Singh, Masaru Suzuki
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Publication number: 20040209169Abstract: A method of verifying the placement of sub-resolution assist features (SRAFs) in a photomask layout is described. SRAFs are added to the photomask layout to enhance the process window for semi-isolated and isolated features. Rules are provided to automatically place the SRAFs into the layout. When deficiencies are detected in the assist feature design or in the automated SRAF placement program, the placement of SRAFs requires verification. The method verifies the correct placement by defining a unique image property linked to the accurate placement of the assist features, and combines it with in-situ image simulation of the individual layout.Type: ApplicationFiled: April 15, 2003Publication date: October 21, 2004Applicant: International Business Machines CorporationInventors: Yuping Cui, Rama Nand Singh
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Patent number: 6803972Abstract: A class of novel structures which make novel use of polymer based reflective polarizing films in an improved polarization conversion system which are useful in liquid crystal projection systems that are easily manufactured, of lower cost, and permit the versatility of higher numerical aperture polarization conversions. Another aspect of the present invention are polarization modulating liquid crystal projection display systems utilizing the polarization conversion systems of the present invention.Type: GrantFiled: November 20, 1997Date of Patent: October 12, 2004Assignee: International Business Machines CorporationInventors: Russell Alan Budd, Derek Brian Dove, Rama Nand Singh
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Patent number: 6791639Abstract: In a liquid crystal display device of a direct view type, a lenticular lens sheet is provided in the backside of a liquid crystal display panel. Light emitted to a lens of the lenticular lens sheet is first converged in the liquid crystal display panel, and then diffused. When the light is emitted from the liquid crystal display panel, the radiation distribution thereof is widened. Thus, a bright display screen even when seen from a wide angle can be realized.Type: GrantFiled: May 14, 2002Date of Patent: September 14, 2004Assignee: International Business Machines CorporationInventors: Evan George Colgan, Fuad Elias Doany, Rama Nand Singh, Masaru Suzuki
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Publication number: 20030214615Abstract: In a liquid crystal display device of a direct view type, a lenticular lens sheet is provided in the backside of a liquid crystal display panel. Light emitted to a lens of the lenticular lens sheet is first converged in the liquid crystal display panel, and then diffused. When the light is emitted from the liquid crystal display panel, the radiation distribution thereof is widened. Thus, a bright display screen even when seen from a wide angle can be realized.Type: ApplicationFiled: May 14, 2002Publication date: November 20, 2003Applicant: International Business Machines CorporationInventors: Evan George Colgan, Fuad Elias Doany, Rama Nand Singh, Masaru Suzuki
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Publication number: 20030165013Abstract: An illumination system and display are disclosed that include a light for providing light, a polarizing beam splitter (PBS) having a first surface that receives the light from the backlight. The PBS passes a first polarization of the received light to a curved mirror located at a second PBS face, which second PBS face is opposite the first PBS face. The curvature of the mirror provides the optical power necessary for proper imaging, while limiting the reflecting area of the mirror provides an aperture stop that determines the numerical aperture of the optical system. The display also includes a quarter wave plate and a spatial light modulator (SLM). The quarter wave plate is located between the PBS and mirror and changes the first polarization of light, directed from the PBS to the mirror, to a second polarization which is reflected from the mirror back to the PBS.Type: ApplicationFiled: March 11, 2003Publication date: September 4, 2003Applicant: International Business Machines CorporationInventors: Fuad Elias Doany, Rama Nand Singh
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Patent number: 6587151Abstract: On a portable computer, a video camera is integrated as a feature by mounting the camera as an assembly made up of a lens and associated pixel electronics in a camera base that is positioned on the perphery of the display in the cover of the portable computer when the cover is open, and the providing of a cavity in the base portion of the portable computer positioned so that the camera assembly enters the cavity when the cover of the portable computer is closed.Type: GrantFiled: August 26, 1998Date of Patent: July 1, 2003Assignee: International Business Machines CorporationInventors: Thomas Mario Cipolla, Rama Nand Singh
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Publication number: 20020196405Abstract: A display device and method for fabricating a liquid crystal cell are disclosed. A liquid crystal cell includes a first substrate, and a second substrate attached to the first substrate. The first substrate has a same thickness as the second substrate. The first substrate is lapped at a first rate while concurrently lapping the second substrate at a second rate, which is different from the first rate. The first substrate and the second substrate are thinned to different thicknesses. The thinner of the first and second substrates is provided on a viewer side of a collimate and post diffuse type liquid crystal cell to reduce depixelization.Type: ApplicationFiled: June 26, 2001Publication date: December 26, 2002Applicant: International Business Machines CorporationInventors: Evan George Colgan, Fuad Elias Doany, Tomohito Jounai, Satoshi Maruyama, Hideo Ohkuma, Rama Nand Singh, Masaru Suzuki
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Patent number: 6310713Abstract: An illumination system and display are disclosed that include a light for providing light, a polarizing beam splitter (PBS) having a first surface that receives the light from the backlight. The PBS passes a first polarization of the received light to a curved mirror located at a second PBS face, which second PBS face is opposite the first PBS face. The curvature of the mirror provides the optical power necessary for proper imaging, while limiting the reflecting area of the mirror provides an aperture stop that determines the numerical aperture of the optical system. The display also includes a quarter wave plate and a spatial light modulator (SLM). The quarter wave plate is located between the PBS and mirror and changes the first polarization of light, directed from the PBS to the mirror, to a second polarization which is reflected from the mirror back to the PBS.Type: GrantFiled: April 7, 1997Date of Patent: October 30, 2001Assignee: International Business Machines CorporationInventors: Fuad Elias Doany, Rama Nand Singh
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Publication number: 20010026398Abstract: An illumination system and display are disclosed that include a light for providing light, a polarizing beam splitter (PBS) having a first surface that receives the light from the backlight. The PBS passes a first polarization of the received light to a curved mirror located at a second PBS face, which second PBS face is opposite the first PBS face. The curvature of the mirror provides the optical power necessary for proper imaging, while limiting the reflecting area of the mirror provides an aperture stop that determines the numerical aperture of the optical system. The display also includes a quarter wave plate and a spatial light modulator (SLM). The quarter wave plate is located between the PBS and mirror and changes the first polarization of light, directed from the PBS to the mirror, to a second polarization which is reflected from the mirror back to the PBS.Type: ApplicationFiled: June 7, 2001Publication date: October 4, 2001Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Fuad Elias Doany, Rama Nand Singh
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Publication number: 20010013972Abstract: An illumination system and display are disclosed that include a light for providing light, a polarizing beam splitter (PBS) having a first surface that receives the light from the backlight. The PBS passes a first polarization of the received light to a curved mirror located at a second PBS face, which second PBS face is opposite the first PBS face. The curvature of the mirror provides the optical power necessary for proper imaging, while limiting the reflecting area of the mirror provides an aperture stop that determines the numerical aperture of the optical system. The display also includes a quarter wave plate and a spatial light modulator (SLM). The quarter wave plate is located between the PBS and mirror and changes the first polarization of light, directed from the PBS to the mirror, to a second polarization which is reflected from the mirror back to the PBS.Type: ApplicationFiled: April 7, 1997Publication date: August 16, 2001Inventors: FUAD ELIAS DOANY, RAMA NAND SINGH
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Patent number: 6247816Abstract: An optical system for a projection display employing three reflective spatial light modulations (SLM's) is described. Two or the three SLM imaging paths employ typical image combining and projection optical techniques. However, the third SLM imaging path employs a relay lens to produce an intermediate image of the SLM which is subsequently combined with the other two images. Each color component is directed onto one of three SLM's, each through its own polarizing beamsplitter (PBS) cube. In two of the three SLM's, image forming light is reflected from each SLM and passes through its respective PBS, and the two colors are then recombined using a dichroic coating. A lens then images the two-color image, and projects it onto a screens. The third SLM traverses a completely separate path. In this case, the image forming light reflected by the SLM and passing through the PBS is first imaged by a relay lens of approximately unity magnification to produce an intermediate image plane.Type: GrantFiled: August 7, 1997Date of Patent: June 19, 2001Assignee: International Business Machines CorporationInventors: Thomas Mario Cipolla, Fuad Elias Doany, Robert Lee Melcher, Rama Nand Singh